This invention relates to a propulsion system for an iceberg, and, in particular, it relates to a system for converting the iceberg into a self-propelled vessel.
Fresh water has long been recognized as the most important of the earth's resources. In fact, it has been stated that the availability of fresh water defines the limits of human activity.
Water is hardly a scarce resource; approximately 1.4 billion cubic kilometers of it cover approximately 80 percent of the earth's surface. However, of this amount, only about 9 million cubic kilometers (about 6/10 of one percent of the total) is both liquid and fresh. Although 9 million cubic kilometers is still a large quantity of water, this total supply is unevenly distributed throughout the earth. Thus, there are vast land areas which are too arid to support any significant degree of human activity, particularly agriculture.
With the world's human population growing rapidly, the need to bring these vast arid areas under cultivation is becoming more and more acute. In order to do so, however, vast quantities of fresh water must be supplied. Currently, the most popular concept for supplying large quantities of irrigation water to these arid areas is that of sea water desalination. However, this concept has achieved only limited success in practice, largely due to the great costs involved in constructing and operating sea water desalinating plants.
However, in recent years, increasing recognition is being given to the fact that vast quantities of fresh water are stored in the form of ice. In fact, approximately 30 million cubic kilometers of fresh water, or about 3/4 of the total world supply of this substance, is in the frozen state. About 90 percent of this ice is contained in the continental ice sheet and the ice shelves of Antarctica, with most of the rest being contained in the Greenland ice sheet. The major obstacle to the utilization of this vast store of fresh water has been the problem of transporting the ice from the ice sheet to the areas where the water is needed. Until now, the only solution which has been proposed to this problem is that of capturing the massive icebergs which break off of these sheets and towing them across vast expanses of ocean to seaports where the icebergs can be controllably melted to supply fresh water. That the current state of the art is limited to the concept of towing the icebergs is amply demonstrated in an article entitled "The Iceberg Cometh" by W. F. Weeks and Malcolm Mellor, appearing in Technology Review, Volume 81, No. 8, August/September 1979.
However, the concept of towing an object as immense as an iceberg is not without great difficulties, such as, for example, the tremendous amounts of fuel that would be consumed by the towing vessels and the difficulty in maneuvering and controlling the iceberg under tow. These practical considerations have confined the towing concept to the drawing board, so to speak. Thus, to date, there has been no attempt to tow an iceberg any appreciable distance. In fact, the only successful iceberg towing which has been accomplished has been that of towing an iceberg a relatively short distance for the purpose of deflecting the iceberg from a collision course with an offshore structures, such as a drilling rig.
Since the concept of towing icebergs has not yet proved its feasibility, there is a growing need for alternative methods of iceberg transportation which would avoid the difficulties which have heretofore kept the towing concept from fruition. One such concept would be that of converting the icebergs themselves into self-propelled vessels. Such a concept was first developed during World War II, when the British Navy investigated the possibility of using modified icebergs as "unsinkable" aircraft carriers to be used in the invasion of Japan. In accordance with this concept, it was proposed to drive the icebergs or "bergships" with about 20 electric motors of approximately 1100 horsepower each, powered by a 24 megawatt turbo electric generator. None of these bergships were ever built, and the project was abandoned in 1944.
While the British bergship concept would have many advantages over towing, particularly with regard to the ability to maneuver and navigate the iceberg, this concept has been largely ignored by those presently involved in the study of iceberg transportation, primarily because of the great costs involved in constructing the necessary turbo-electric generators, as well as the expense of operating these units in view of the massive fuel requirements involved.
In view of the foregoing discussion, it can be readily appreciated that providing a "bergship" with a relatively low cost, highly energy efficient propulsion system would solve the major problems heretofore encountered in the area of iceberg transportation, and would therefore prove to be of incalculable value in allowing mankind to unlock nature's greatest storehouse of the earth's most valuable resource.